Miller Park and the Rogers Centre, home of the Milwaukee Brewers and Toronto Blue Jays respectively are retractable roof stadiums whose primary function is to keep their fans warm during baseball season’s colder months. As the majority of the season is in the northern summer, unlike Minute Maid Park and Marlins Park, these two facilities keep their roofs open for more than half their teams’ home games. A close inspection of the two buildings shows few further similarities however.

Miller Park opened in 2001, replacing nearby County Stadium, an open-air venue that housed Brewer baseball since 1953.

Aerial view of Miller Park via Bing

Designed by the team of NBBJ of Seattle and HKS of Dallas, the new stadium footprint follows the shape of the baseball diamond, with the two sides of the roof sitting atop each baseline. The fan-shaped roof is unlike any retractable roof in the world. When activated, the two sides come together directly above centerfield in a speedy ten minutes. The impressive yet complicated roof structure has had several repairs in the ten years it has been in operation including a $13 million overhaul in 2006.

The glass wall above the third baseline has been problematic, however, as the shadows on the field created by the setting sun proved dangerous for both batter and pitcher. A solution was discovered in 2010 when the Brewers decided to close the western half of the roof during games, throwing a consistent shadow over the majority of the field. Unfortunately the result is that the stadium only opens to a small patch of sky – beautiful weather or not.

Miller Park is designed to evoke stadiums of yesteryear and sits firmly in the retro-stadium movement. The compact, 42,000-seat stadium has the requisite brick and limestone façade and asymmetrical outfield to suggest it’s a vintage park of the previous century. The park is also loaded with quirky features, like a multi-storey slide beyond the left field wall that Bernie Brewer slides down following Brewer homeruns, while a 6th Inning Sausage Race keeps fans happy and cheerful regardless of the score.

The famous Brewers’ Sausage Race with Bernie’s slide in background via Wikipedia

Miller Park is generally in the top-10 in attendance every year and was voted Best Stadium in MLB this year in an ESPN poll. It has to be considered an upgrade over its predecessor and the high-arching roof cuts an iconic profile that matches the soaring roof of the nearby Milwaukee Art Museum, designed by Spanish Architect/Engingeer Santiago Calatrava. However, the troubled, brief history of the roof is cause for concern and makes one worry about its tenure going forward.

The Rogers Centre is the oldest of the six retractable stadiums in MLB, having opened in 1989 (as the SkyDome), and represents a fundamentally different approach to a retractable facility than its counterparts.

The Rogers Centre is designed to be a closed with the option of opening, instead of opened with the option of closing. Although natural grass could grow should the roof be opened the majority of the time, the field at the Rogers Centre is synthetic FieldTurf that can easily be removed if need be. This flexibility allows for mid-season functions other than baseball in season and a variety of events throughout the harsh Toronto winter. Though the Blue Jays are the prime tenant, they share the 23-year old building with the Toronto Argonauts of the Canadian Football League, the NBA’s Raptors (between 1995 and 1999), soccer matches, music concerts, motor sports and trade shows, such that the Rogers Centre is in use for nearly half the calendar year, making it the most used large stadium in North America.

Designed by relatively unknown architect Rod Robbie, the Rogers Centre is located in downtown Toronto on the shore of Lake Ontario and accessed by train that arrives at the front door. The roof of the 50,000-seat stadium is designed in four parts and when opened offers views to the neighboring CN Tower, soaring 1,800 feet above.

The 31-storey, semi-circular roof sits high above the Blue Jay outfield and allows 91% of the seats to be open to the sky above. The whole atmosphere of the Rogers Centre is decidedly modern, from its abstract white, semi-circular roof above, to the synthetic field turf surface below. However, it is also kind of a throwback to the big, multi-purpose stadiums of a generation ago. A 348-room hotel forms the northern edge of the building, with 70 rooms overlooking the playing field, along with numerous restaurants and a health club with the world’s largest indoor track. The diversity of uses for the Rogers Centre seem real and genuine in comparison to the gimmicky night club at Marlins Park or Bernie’s slide at Miller Park.

Despite its exciting amount of uses, the Rogers Centre is not the best place to watch a baseball game. There are seats in the fifth deck tucked up next to the hotel, where one literally can’t see the outfield. It is big and cavernous and it is the only playing field in baseball without a dirt infield; this 1980s stadium is very much a relic of its decade.

The famous hotel sits beneath an open Rogers Centre roof via Nature Notes

Somewhere between pseudo-historic stadiums like Miller Park and hulking giants like the Rogers Centre, lies the perfect ballpark. It is an intimate place where fans feel part of the game but not patronized by gimmicky, overly quirky stadium features. It is an architecturally forward-looking, well-used building capable of adapting to changing weather patterns, whose size and style does not alienate its loyal baseball fan base. Our pursuit of such a stadium continues – although the journey might be more interesting than the destination.